ISIS early Sunday morning released a 15-minute video purportedly showing the beheading of American aid worker Peter Kassig in Syria.
The video was posted on social media has not been confirmed as genuine and it is not clear that footage depicts Kassig, 26, from Indiana.
“We are aware of a video that claims to show the murder of U.S. citizen Peter Kassig by ISIL. The intelligence community is working as quickly as possible to determine its authenticity,” National Security Council Spokesperson Bernadette Meehan said.
Kassig worked for charity groups in Lebanon and Syria and was captured in Syria by militants in October last year.
During his captivity, his family says Kassig converted to Islam and changed his name to Abdul-Rahman, which means “servant of the most merciful.”
The video also shows other men being beheaded.
In the video, a militant clad in black with a concealed face is pictured next to a severed head that is said to be Kassig’s.
“Here we are, eagerly awaiting for the remainder of your crusading armies to arrive,” Kassig’s purported executioner says in the video, addressing President Obama and the West.
Kassig’s family or their representatives were not immediately available for comment.
Last month Kassig’s parents released parts of a letter written to them by their son.
“Don’t worry dad, if I go down, I won’t go thinking anything but what I know to be true. That you and mom love me more than the moon and the stars,” Peter Kassig wrote.